Kinetic and stability analysis of PKU mutations identified in BH4-responsive patients

From all the different molecular mechanisms put forward to explain the basis of BH4 responsiveness in PKU patients, a clear picture is now emerging based on the results from expression studies performed with a number of missense mutations identified in patients with a positive response in BH4 loading tests. Two of the proposed mechanisms, namely decreased binding affinity of the mutant proteins for the natural cofactor and stabilization effect of BH4, have been confirmed for several PKU mutations and the results are reviewed here. The actual view supports a multifactorial basis of the response, highlighting the necessity of detailed in vitro characterization of each mutant PAH protein. Several of the confirmed molecular mechanisms may be operating simultaneously, as exemplified in the data presented, and this may result in different degrees of BH4 responsiveness.     

Induction of peptide-specific primary cytotoxic T lymphocyte responses from human peripheral blood

Various protocols were developed and compared for eliciting specific cytotoxic T lymphocyte (CTL) cell lines from the unselected human peripheral blood mononuclear cells of naive donors. Interleukin-7 and CD4⁺ T cells primed in vitro by keyhole limpet hemocyanin were shown to act together in the generation of these responses. Primary responses were consistently induced with a variety of different HLA class I-binding malarial peptides. Primary CTL responses could be induced from unselected CD8⁺ and from CD45RA⁺CD8⁺ T cells. The CTL lines derived from these naive donors were CD8⁺ and demonstrated a high level of HLA class I-restricted killing for > 3 months after priming in vitro. They were also able to recognize and kill targets infected with a recombinant vaccinia virus containing the full-length antigen. In addition, this same protocol enhanced up to fourfold the levels of secondary CTL responses induced. The optimal method presented for naive cytotoxic T cell stimulation is simple, rapid and generally applicable and should provide a useful tool for both basic research and human therapy.     

Distribution of CGG repeats and FRAXAC1/DXS548 alleles in South American populations

In order to assess the molecular variability related to fragile X (FMR1 locus), we investigated the distribution of CGG repeats and DXS548/FRAXAC1 haplotypes in normal South American populations of different ethnic backgrounds. Special attention was given to Amerindian Wai-Wai (Northern Brazil) and Ache (Paraguay), as well as to Brazilian isolated communities of African ancestry, the remnants of quilombos. Comparison of samples from quilombos, Amerindians, and the ethnically mixed, but mainly European-derived population of S?o Paulo revealed that the 30-copy allele of the fragile X gene is the most frequent in all groups. A second peak at 20 repeats was present in the population of S?o Paulo only, confirming this as a European peculiarity. The distribution of DXS548 and FRAXAC1 alleles led to a high expected heterozygosity in African Brazilians, followed by that observed in the population of S?o Paulo. Amerindians showed the lowest diversity in CGG repeats and DXS548/FRAXAC1 haplotypes. Some rare alleles, for example, the 148-bp (FRAXAC1) or 200-bp (DXS548) variants, which seem to be almost absent in Europe, occurred in higher frequencies among African Brazilians. This suggests a general trend for higher genetic diversity among Africans; these rarer alleles could be African in origin and would have been lost or possibly were not present in the groups that gave rise to the Europeans.     

Celiac disease: understanding the gluten-free diet

Purpose

The only effective and safe treatment of celiac disease (CD) continues being strict exclusion of gluten for life, the so-called gluten-free diet (GFD). Although this treatment is highly successful, following strict GFD poses difficulties to patients in family, social and working contexts, deteriorating his/her quality of life. We aimed to review main characteristics of GFD with special emphasis on factors that may interfere with adherence to it.

Methods

We conducted a search of various databases, such as PubMed, Google Scholar, Embase, and Scielo, with focus on key words such as “gluten-free diet”, “celiac disease”, “gluten” and “gluten-free diet adherence”. Available literature has not reached definitive conclusions on the exact amount of gluten that is harmless to celiac patients, although international agreements establish cutoff points for gluten-free products and advise the use of clinical assessment to tailor the diet according to individual needs. Following GFD must include eliminating gluten as ingredient as well as hidden component and potential cross contamination in foods. There are numerous grains to substitute wheat but composition of most gluten-free products tends to include only a small number of them, especially rice. The diet must be not only free of gluten but also healthy to avoid nutrient, vitamins and minerals deficiencies or excess. Overweight/obesity frequency has increased among celiac patients so weight gain deserves attention during follow up. Nutritional education by a trained nutritionist is of great relevance to achieve long-term satisfactory health status and good compliance.

Conclusions

A balanced GFD should be based on a combination of naturally gluten-free foods and certified processed gluten-free products. How to measure and improve adherence to GFD is still controversial and deserves further study.

     

The Emerging Role of the Double-Edged Impact of Arachidonic Acid-Derived Eicosanoids in the Neuroinflammatory Background of Depression

Eicosanoids are arachidonic acid (AA) derivatives belonging to a family of lipid signalling mediators that are engaged in both physiological and pathological processes in the brain. Recently, their implication in the prolonged inflammatory response has become a focus of particular interest because, in contrast to acute inflammation, chronic inflammatory processes within the central nervous system (CNS) are crucial for the development of brain pathologies including depression.The synthesis of eicosanoids is catalysed primarily by cyclooxygenases (COX), which are involved in the production of pro-inflammatory AA metabolites, including prostaglandins and thromboxanes. Moreover, eicosanoid synthesis is catalysed by lipoxygenases (LOXs), which generate both leukotrienes and anti-inflammatory derivatives such as lipoxins. Thus, AA metabolites have double-edged pro-inflammatory and anti-inflammatory, pro-resolving properties, and an imbalance between these metabolites has been proposed as a contributor or even the basis for chronic neuroinflammatory effects.This review focuses on important evidence regarding eicosanoid-related pathways (with special emphasis on prostaglandins and lipoxins) that has added a new layer of complexity to the idea of targeting the double-edged AA-derivative pathways for therapeutic benefits in depression. We also sought to explore future research directions that can support a pro-resolving response to control the balance between eicosanoids and thus to reduce the chronic neuroinflammation that underlies at least a portion of depressive disorders.     

Efficacy and safety of daclatasvir‐based antiviral therapy in hepatitis C virus recurrence after liver transplantation. Role of cirrhosis and genotype 3. A multicenter cohort study

Direct‐acting antiviral agents (DAA) combining daclatasvir (DCV) have reported good outcomes in the recurrence of hepatitis C virus (HCV) infection after liver transplant (LT). However, its effect on the severe recurrence and the risk of death remains controversial. We evaluated the efficacy, predictors of survival, and safety of DAC‐based regimens in a large real‐world cohort. A total of 331 patients received DCV‐based therapy. Duration of therapy and ribavirin use were at the investigator's discretion. The primary end point was sustained virological response (SVR) at week 12. A multivariate analysis of predictive factors of mortality was performed. Intention‐to‐treat (ITT) and per‐protocol SVR were 93.05% and 96.9%. ITT‐SVR was lower in cirrhosis (n = 163) (96.4% vs. 89.6% P = 0.017); the SVR in genotype 3 (n = 91) was similar, even in advanced fibrosis (96.7% vs. 88%, P = 0.2). Ten patients (3%) experienced virological failure. Therapy was stopped in 18 patients (5.44%), and ten died during treatment. A total of 22 patients (6.6%) died. Albumin (HR = 0.376; 95% CI 0.155–0.910) and baseline MELD (HR = 1.137; 95% CI: 1.061–1.218) were predictors of death. DCV‐based DAA treatment is efficacious and safe in patients with HCV infection after LT. Baseline MELD score and serum albumin are predictors of survival irrespective of viral response.     

Coital incontinence: a factor for deteriorated health-related quality of life and sexual function in women with urodynamic stress urinary incontinence

Introduction and hypothesis

To assess the impact of coital incontinence (CI) on health-related quality of life (HRQoL) and quality of sexual function (QSF) in women with urodynamic stress urinary incontinence (SUI).

Methods

Women were recruited for this cross-sectional study from among 289 patients with lower urinary tract symptoms, underwent clinical and urodynamic evaluation. Of these 289 women, 127 sexually active women with SUI completed the King’s Health Questionnaire (KHQ) and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ), of whom 97 were enrolled for the study. The study group comprised 53 women with CI occurring ‘sometimes’, ‘usually’ or ‘always’, and the control group comprised 44 women without CI. Total and individual domain scores were evaluated.

Results

CI was reported by 65.35 % of the women. The frequency of CI was correlated with lower educational level and higher body mass index (r?=?0.22 and r?=?0.23, respectively; p?=?0.01). The KHQ results showed significantly lower HRQoL in women with CI in all domains (p?<?0.05) apart from Sleep/energy’ (p?=?0.054). PISQ revealed no significant differences in QSF in the Behavioral/emotive and Partner–related domains (34.3?±?10.0 vs. 33.0?±?12.2 and 18.0?±?2.9 vs. 18.2?±?3.6, respectively). Women with CI reported a significantly lower QSF in the Physical domain (29.1?±?6.6 vs. 35.0?±?4.6, p?=?0.001), and the total PISQ score was lower but the difference was not significant (81.4?±?14.3 vs. 86.2?±?16.5). Total PISQ score was correlated with age (r?=??0.28, p?=?0.001). Women with CI were significantly more likely to admit that fear of incontinence or fear of embarrassment restricted their sexual activity (p?<?0.001).

Conclusions

A large percentage (65.35 %) of women with SUI reported CI, which had a negative impact on HRQoL and QSF in the Physical domain, but no significant impact on overall QSF.